摘要：
Convert a non-negative integer to its english words representation. Given input is guaranteed to be less than 231 - 1. Example 1: Example 2: Example 3 阅读全文
摘要：
Every email consists of a local name and a domain name, separated by the @ sign. For example, in alice@leetcode.com, alice is the local name, and leet 阅读全文